Interpreting pronation excursion MP to TO data


I was running on the treadmill yesterday and stopped mid-run to make an adjustment to my insoles. Directly underneath the ball of my foot (big toe) I have a couple layers of felt about the size of a quarter. During the run, I believed that I was landing too much on the outside of the right foot, feeling I had lifted the ball of t hat foot up too much. It was causing pain on the inside of my ankle. So I stopped and removed the padding. It’s just a couple of mm’s. Much to my surprise, when I looked at my data after the run I saw this:

Wow - that’s quite a change for just a few mm’s of padding.

Today - I thought I would try to get the feet matched up, so removed the padding on the other foot, expecting the line to also move towards “0”. Instead, I see this:

So when I do the same thing to both feet - why does this metric move towards “0” on one foot and away from “0” on the other foot. Should I interpret this to mean that instead of removing material on the second foot, I should double the thickness? Or perhaps is the data getting interpreted in the wrong direction?


Hi @runnerdave – your experiment is pretty interesting – very cool to see the impact a small change can make. Pronation is another one of those very individual gait mechanics.

We capture Pronation from FS (FootStrike) to the point of MP (MaxPronation / foot flat) – this is the first/absorptive phase of your footstrike, and the one that we report as a core metric. It is the difference in the angles at the two points, so represents how much ‘roll’ your foot goes through. We also capture Pronation from MP to TO (ToeOff) – this is second/propulsive phase, which we only report for researchers, as it is will change depending on mounting location (as your foot/shoe flexes at TO).

If you are working on your symmetry, I would focus on Pronation FSMP, as what happens between FS and MP is where you are absorbing the load of footstrike.